Hello Peter and thanks for your interest in Cork.
I'm not working on the Mongo backend at the moment but I would be happy to spend
some time on it. All the code under development is on GitHub.
Please fork my repository if you want to get started.
Also, I've created a feature request for MongoDB on:
https://github.com/FedericoCeratto/bottle-cork/issues/8
If anyone else is intrested in it, please upvote the issue.
Thanks,
--
Federico